Monthly Archives: August 2009

Before cash, there was land. The family held some, and grew rice on it. It was passed to the children — the sons anyway. Divided among them. They passed it to their sons in turn, and the soil split into fractals. But the people didn’t get smaller too, and so they began to starve. This process is still going on in places like Ethiopia, Bangladesh, Laos.

Yet we in the industrialized world seem astonished that our parents could afford the houses that we cannot.

The economics of sustenance farming in the face of rising population are immediately clear, yet we do not take the general lesson. We still act like we have infinite resources. Our population is still increasing, yet land, water, oil, and every single mineral is finite and running out. A 2007 article in New Scientist discusses this more cogently than anything I’ve ever seen, including the above chart “How Long Will It Last?”

We need to apply the same thinking to energy. I am not talking about running out of oil. The oil will run out, of course, and not before we do tremendous environmental damage — I, for one, am planning on hitting the world’s great beaches sooner rather than later. But when the oil is gone, it’s simply gone. Unlike copper or plastic, energy cannot be recycled in any way (in fact energy is the limiting input in recycling everything else.) We have no choice but to switch to sunlight for our ongoing power needs. And sunlight, like land, will have to be divided smaller and smaller among more and more of us.

I’m currently looking for an apartment in Hong Kong. On my own I can afford about 200 square feet. I saw a place where the Indonesian nannies live; there were six people in this space, crammed into bunk beds barely narrower than the one tiny room. I was shocked, until I realized that I had arrived in the future. It’s not going to get better. We’re already out of space, but soon we will feel the energy pinch. One day soon, electricity, transport, and hot water are going to be just as rationed as real estate (by each of us individually, because of the cost.)

An engineer named Saul Griffith has done the calculations. To meet the current world population’s current energy requirements, we would need to collect the incident sunlight over an area about the size of Australia. That’s a stupendous amount of solar power to build. It will be a very long time before it is built, if ever. More fundamentally, the physical relationship between incident sunlight and land area brings us right back to passing ever-smaller fields to our children. (By the way, nuclear power won’t help: even without building more power plants we will run out uranium some time in the next century. And wind power, wave power etc. are actually solar driven.)

We will never see the easy material affluence of our parents; we have entered the zero-sum game phase of land- and energy-measured wealth where the only way to get more is to take from someone else (as evidenced by the increasing wealth inequality in industrialized countries over the past few decades.) We can no longer teach our children to expect more than their parents. It’s all a lie; barring insane technological shifts or catastrophic population reduction, the future is high density.

The big house of the American Dream, which is also the big house of the aspiring middle-class everywhere in the world, is over.

I was told in grade school that the giraffe’s neck evolved to be long because taller giraffes could reach more tasty tree leaves in times of drought. It’s a lovely example of natural selection, and also completely wrong, as I discovered when researching an edit to the Wikipedia article. Eventually, someone just went and checked: it turns out that during times of drought or food scarcity, giraffes eat from low bushes.

There is an important lesson here about what it means to “explain something.”

Rudyard Kipling wrote a children’s book of myths about the origins of animals titled Just-So Stories. In it he explains the origin of the elephant’s trunk, how the camel got his hump, and where the leopard’s spots came from (they were drawn by an Ethiopian from the leftover black of his own dark skin, so that the leopard would better blend into the background when they hunted zebra together.) Clearly, making sense is not the criterion for truth. It’s very easy to forget this, when someone gives you a complex explanation and you get that “aha! I understand” feeling. Human beings constantly confuse congruence with truth.

Sensible and false explanations are such a problem in science that the term “just-so story” has come to refer to any sort of explanation that fits the facts, but cannot be verified. Scientific theories are supposed to differ from literary criticism and other forms of creative writing by demanding explanations that are true. This means testing them against reality.

A crucial point here: you can’t test a theory against the same facts that you used to come up with the theory to begin with. Of course a theory is going to fit the facts that inspired it! Instead, a theory — an explanation of something — needs to predict things that haven’t been observed yet. Prediction is the essence of science; it is the ability to say what will happen before it happens that makes it possible to “design” a bicycle rather than just gluing random objects together until they roll. If our aim is to come up with a true theory about evolution, we need to use the length of the giraffe’s neck to make predictions about something else, something we can go check (repeatedly, if we are serious about testing the theory.)

This seemingly philosophical notion is incredibly useful for spotting subtle bullshit that sounds like science.

Consider, for example, the trial of a vitamin for preventing the common cold. Let’s say it’s even a controlled trial. One hundred volunteers are given Vitamin Z daily, while another hundred are (unknowingly) given a placebo. At the end of the study, the Vitamin Z group had the same number of colds. But, the researchers discover as they analyze the data, they had fewer headaches. Does this mean Vitamin Z prevents headaches? Not necessarily, because the theory “Vitamin Z prevents headaches” was formulated by noticing a pattern, any pattern, then making up a story about how that pattern came to be. That doesn’t make the story true. And there will always be patterns. If the volunteers can suffer from hundreds of different ailments, then by sheer dumb chance the Vitamin Z group will be found to suffer from less of at least one of them. (Applied to controlled experiments, this notion can be made mathematically precise, by the way. See post-hoc analysis.)

Put another way, if you keep turning over rocks you will eventually find something. The whole point of a theory — an explanation, a model, a statement of the causal relationships of reality — is to say what you will find before the rock is turned over. Otherwise you only have a story that fits the facts, a just-so story.

I have found just-so stories to be most common in alternative medicine, economics, and evolutionary explanations of human behavior. If nothing testable has been predicted, then nothing has been “explained.”